Sewing-machine brake.



A RACK.

SEWING MACHINE BRAKE.

APPLICATION FILED APR-13.1915- l l 72, 1 66. Patented Feb. '15, 1916.

wil I l wi bnemo I THE COLUMBIA PLANODRAPH c0, WASHINGTON, D. c.

ALEXANDER RACK, O1 PHILADELPHIA, PENNSYLVELNIA.

SEVTING-MACI'TINE Application filed April 13, 1915.

To all 'w/iom it may concern:

Be it known that l, ALEXANDER RACK, a subject of the Emperor of Austriwliungary, residing at Philadelphia, in the county of Philadelphia State of Pennsylvania, have invented new and useful improvements in Sewingdifachine Brakes, of which the following is a specification.

ily invention relates to brakes and more particularly to sewing machine brakes.

T he object of the invention is to provide a device of the character described which will embody a brake shoe of such formation as to effectively grip the drive pulley and thereby serve as a positive stop for the sewing machine.

Another object of the invention is to provide a brake that may be actuated by the operators knee.

Another object of the invention is to provide a braking mechanism that is simple and eflicient in construction and which may be manufactured at a nominal cost.

In the accompanying drawings: Figure 1 is an elevation of my device showing it applied to a sewing machine. Fig. 2 is a transverse section of the brake taken through the line 2-2. Fig. 3 is a transverse section of the rake tl rough the line 3-3 and showing the relative position of the brake shoe to the drive pulley.

Similar numbers designate corresponding parts in all of the views of the drawings.

Beferring to the drawings, 1 is a sewing machine including a work table 2 having depending bearings 3 secured to the under side thereof and adjacent opposite ends. A horizontal shaft 5 is journaled in the bearings 3 and is provided with a laterally extending crank arm 6 rigidly mounted on one end thereof, and an arcuate shaped crank arm 7 rigidly secured to the remaining end of the shaft 5 and extending in a direction opposite to the heretofore mentioned crank arm 6. This crank arm 7 has its lower extremity formed into a brake shoe 8 which is ll-shaped in cross section and is adapted to straddle the periphery of the drive wheel 12 as shown.

Secured to the under side of the work table adjacent one end of the shaft 5 is a bracket 9 in which is pivotedly mounted a bell crank lever comprising a substantially horizontal extension 10 adapted to engage the under side of the crank arm 6, and a vertical extension 11 which is widened Specification of Letters Patent.

Fatented Feb. 15, H516.

Serial 11o, 121K242.

throughout a major portion of its length, as at 11 to provide a greater bearing surface.

Formed integrally with and extending upwardly from the bell crank lever at the juncture of the extension of said lever is a lug 13 ada ted to engage the side of the bracket 9 when the bell crank is in inactive position. T he crank arm "'4' is connected to the under side of the work table by a coiled sprii'ig ll which is adapted to exert its contractile for e to disengage the brake shoe 8 from the drive pulley 12 and to restore the braking mechanism to its normal position.

From the foregoing construction it will be seen that when pressure is exerted upon the vertical. extension 11 of the bell crank the horizontal extension 10 will be elevated, which in turn acting upon the crank arm 6 will cause a partial rotation of the shaft 5 moving the shoe 8 into engagement with the lr' e pulley 12 against the tension of the spring ll. It will be noticed that the parallel arms of the brake shoe 8 straddle the drive pulley when in active or inactive position, thereby preventing any longitudinal movement of the horizontal shaft 5 and insuring a proper engagement of the shoe with the pulley.

l claim 1. In a sewing machine brake, the combination of bearings depending from the underside of the machine, a horizontal shaft journaled in said bearings, a crank arm secured to said shaft and lying in the same plane therewith, a second crank arm mounted on the remaining end of said shaft and extending in a direction opposite to the first mentioned crank arm, a shoe formed integral with the free end of the second mentioned crank arm and U-shaped in cross section, bracket secured to the underside of the machine, a hell crank lever pivotedly mounted in said bracket and comprising a substantially horizontal extension and a vertical extension, said horizontal extension adapted to engage the underside of said first mentioned crank arm, and a coil spring l1aving one end secured to the machine and the opposite end attached to the second mentioned crank arm intermediate its ends, said spring adapted to work in opposition to said bell crank.

2. In sewing machine brake, tie combination of bearings depending from the underside of the machine, a horizontal shaft journaled in said bearings, a crank arm se:

cured to saidshaft and lying in the same plane therewith, a second crank arm mounted on the remaining end of said shaft and extending in a direction opposite to the first mentioned crank arm, shoe formed integral With the free end of the second mentioned crank arm and Ushaned in cross section, a bracket secured to the underside of the machine, a bell crank lever pivotedly mounted in said bracket and comprising a substantially horizontal extension and a vertical extension, said horizontal extension adapted to engage the underside of said first mentioned crank arm, and a coil spring having one end secured to the machine and the opposite end attached to the second mentioned crank arm intermediate its ends, said spring adapted to Work in opposition to said bell crank, and a vertically extending lug 20 HELEN G. DALEY, WJS. IviCDOWELL- Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents,

Washington, D. C. 

